Transmission input shaft change?

[OU812]

I am trying to figure out how to mate a Muncie four speed transmission to a Jeep 4.0L. Some of the Muncies came with the 10 spline 1-1/8" input shaft but many come with the 26 spline 1-1/8" input shaft. Other than the clutch and pressure plate, what other parts would I need in order to use the 26 spline input shaft?

Also I am looking for a M20 or M21 tranny if anyone has one they want to sell one shoot me a PM.

[Dukes69]

pressure plate is probably the same 10 to 26 spline. Its possible that the 10 spline cluster gear and the 26 spline cluster are not the same. Chrysler has a 18 and 23 spline 4 speed box, but none of the gears are interchangeable, just the cases. Just something to research.

Whats the purpose of using the muncie as opposed to a tremec or something with an OD? Or even a NV3550, bolt on and go . . . kinda.

[OU812]

Because this is going in my 53 chevy pickup. I like the way the muncies shift and sound. I have a muncie four speed in there now but I think it is the SM465 because it has the ganny first.

[inVERt'D]

Look for a bulge on the passenger side of your tranny, cuz I'm thinking if anything it might be an SM420. The 465 came out in about 1968. Both are great trannies, but the 420 is getting hard to find parts for. It doesn't just have a granny 1st, it has a 7:1 granny 1st which is the lowest light truck transmission I've ever heard of.

Check out Novak's website, there's some potentially useful info on there.

http://www.novak-adapt.com/knowledge...on_gateway.htm

[OU812]

I am not sure which one it is. I am working on pulling it out right now so once it is out Ill try to identify it so I can find a rebuild kit. Its certainly a low first gear though. It may be the SM420 because I think it came out of a 62 chey truck.

[6spdYJ]

Do a search for images of the SM420. I've used transtar industries for rebuild kits. They're fairly priced. You could probably find cheaper, but they're practically local. They have warehouses in Anaheim and Rancho Cucamonga.

[bails85]

dude why the @#$! would u put a jeep motor in a 53 chevy. ur taking this jeepin thing to a whole nother level. just sounds odd to me.

[2blk2drs]

dude why the @#$! would u put a jeep motor in a 53 chevy. ur taking this jeepin thing to a whole nother level. just sounds odd to me.

Why would anyone dump thousands of dollars into a crappy 20 year old jeep?

Face it: We are odd people :p

[OU812]

dude why the @#$! would u put a jeep motor in a 53 chevy. ur taking this jeepin thing to a whole nother level. just sounds odd to me.

Because it's a good motor. It makes plenty of power to turn my 29 inch street tires and it's pretty damn reliable. Also in 1953 you couldn't get a V8 in a chevy. The 216 inline six and it's big brother the 235 inline six are very similar to te Jeep 4.0L. Parts comonality is anoher plus. If both of my cars have the same motor I can share parts. I'm not asking or sugesting anyone else do this. It sounds like fun to me, and that's what I am looking for most out of my car hobbie.

[inVERt'D]

If Scott wanted to follow everyone else, he'd throw in a smallblock V-8, spend a lot of time screwing with carburetor jets or running a TBI, but apparently a tire smoking hotrod isn't what Scott wants his truck to be. He wants to improve his truck without really changing its character too much. The Jeep 4.0 is a lot like his old Chevy 6, just better in every way. It will be a cool, unique truck that should be very reliable and usable. Maybe I'm odd too, but I would be a lot more interested in that project than yet another smallblock transplant. Actually I am odd, but it's still cool.

Scott, I'm no engine swap genius, but I've done this kind of thing before, so I'd be happy to give you the help and advice I wish I'd had before I bought anything.

[OU812]

If you are still around I can tack my two cross members together and bring them to your place for final welding. You are right I am not looking for a 10 second quarter mile car. I really want to use this truck like a truck though. So if it can tow and haul and be reliable when I am done then I’ll be happy. And maybe in a year or so I can turn my 4.0L in to a 4.7L stroker. For a truck with an original top speed of about 45mph it will be pretty quick. It should shine up pretty good too. 90% of people who see it won’t know the difference.

[inVERt'D]

Sure, I'll weld the crap out them crossmembers.

My advice (since you didn't ask for it), is if you're going to go EFI, you will save yourself a lot of time, trouble, and money if you get a fairly complete donor car. A partial list of things you'll need (in addition to the engine and whatever bolts to it) would be the wiring harnesses (some of which will be inside the vehicle) including relays, etc., the fuel system including lines, the fuel tank, pump, etc., various sensors (MAP, etc) the exhaust including manifold, headpipe, 02 sensors, etc. Speedometer may be an issue as the Jeep ECU will want vehicle speed sensor. I'd call Novak and Advance Adapters and see what they have for that or what advice they could give you.

[OU812]

I've been eyeballing some cheep($600) 2wd XJs. Ugly as sin but have most of the parts Ill need.

[Materdaddy]

...get a fairly complete donor car...

He has that awful blue thing that he could gut as a donor car.

[OU812]

He has that [COLOR="Red"]AWESOME [/COLOR]blue thing that he could gut as a donor car.

Fixed it.:thumbs_up